list_virtual_display_windows

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe read operation. The description consistently describes a listing operation but adds little beyond the annotations beyond mentioning the return format and the Xvfb context. No additional behavioral traits (e.g., error handling, need for an active display) are disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, front-loaded with the main action, and includes a clear structured Args/Returns breakdown. Every sentence is informative and there is no waste or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read-only tool with one parameter and annotations that declare its safety, the description covers the purpose, the parameter, and the return format. It lacks usage guidelines and prerequisite details, but given the tool's simplicity and the output schema, it is sufficiently complete for an agent to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% for the outer 'params' parameter, but the description merely says 'display number', which is already provided in the inner schema's description for the 'display' property. This is redundant and adds no meaningful clarification beyond what the agent would already find by examining the parameter schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb 'List' and clearly identifies the resource as 'windows on an Xvfb virtual display'. This distinguishes it from sibling tools like list_windows or list_headless_windows by explicitly scoping to Xvfb virtual displays, making it immediately clear what the tool does.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives, nor does it mention any prerequisites or exclusions. While the name is somewhat self-explanatory, there is no explicit direction for an agent to select it over sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.